Copy Data From Staging Table To Production?

I am trying to insert data from staging table to production table. In the staging table I only have period or date but no primary key.

This is my staging table

Create stagingtable(
[Period] [char](7) NOT NULL,
[CompanyCode] [varchar](100) NOT NULL,
[total] [int] NULL,
[status] [varchar](50) NULL
)

Create Production(
[Period] [char](7) NOT NULL,
[CompanyCode] [varchar](100) NOT NULL,
[total] [int] NULL,
[status] [varchar](50) NULL
)

I get this every month. What can I do to make sure only unique record are loaded into production table with no duplicate from previous month.